One such drill is known from the relevant state of the art, namely German U.S. Pat. No. 4,493,596. The drill described in this publication is provided with fastening elements in the form of screws that hold the cutting insert in the groove of the shaft, namely by being screwed down against the groove side walls. For this purpose, the cutting insert is provided with at least one bore that is arranged perpendicular to the transverse axis and perpendicular to the longitudinal axis of the drill, with a screw passing through said bore. In this case, the screw head is preferably realized as a countersunk head that lies in a corresponding counterbore of the cutting insert in such a way that the screw head is flush with the surface of the cutting insert or countersunk in said surface. However, in one preferred embodiment with two bores, the screw is arranged in such a way that the screw head lies in one cutting surface, with a threaded screw shaft exiting the rear side surface of the cutting insert that is situated opposite to the cutting surface and engaging into a threaded bore arranged in the corresponding groove side wall. The central axes of the bores provided in the cutting insert for accommodating the fastening screws as well as the central axes of the threaded bores provided in the groove side walls for accommodating the threaded part of the fastening screws are in this case arranged somewhat offset to one another such that when inserting a screw provided with a countersunk head, as force is exerted that moves the cutting insert in the direction toward the groove bottom such that it adjoins said groove bottom.
However, the previously described state of the art is associated with the disadvantage that the screw heads that are arranged in the cutting surfaces of the cutting insert impair the direct discharge of the chips. In addition, the bores provided in the cutting insert for accommodating the fastening screws weaken the cutting insert, so that the cutting insert must have a relatively large extent in the longitudinal direction of the drill in order to compensate for the aforementioned weakening. According to the relevant state of the art, the ratio between the diameter of this drill, i.e., the distance of the adjacent cutting edges to one another, and the height of the cutting insert is relatively small. At a given diameter, this leads to a relatively large extent of the cutting insert in the longitudinal direction of the drill and consequently a weakening of the tip of the drill
U.S. Pat. No. 4,768,901 discloses a drilling tool with two or more cutting edges in which interchangeable cutting elements are fastened in correspondingly designed recesses in the drill tip by means of screws. In this case, the interchangeable cutting elements are provided with fastening sections that are situated behind the main cutting edge, as viewed in the cutting direction. Each respective fastening section is provided with a bore that accommodates the screws which engage into threaded bores that are arranged in the face side of the drill tip and extend parallel to the drill axis. According to this state of the art, the fastening screws are arranged parallel to the drill axis, with a separate cutting element or a separate cutting insert being provided for each respective main cutting edge. This state of the art is also associated with the disadvantage that the fastening screws extend through bores in the cutting insert, so that bores that limit the geometric design possibilities and require a correspondingly large size of the cutting inserts need to be provided in the cutting elements.